How do incinerating toilets work?

These potties give 'fire in the hole' a whole new meaning.

Q: I recently got the grand, envy-inducing tour of the super fancy new boathouse my brother-in-law built on his waterfront property … a Sunset magazine-worthy affair if there ever was one. Given that it’s somewhat of a perilous hike up a steep embankment to the main house — and the commode — I asked him how he handled trips to the little boy’s room. “I’ve got that covered,” he explained as he led me around to the side of the boathouse and revealed a somewhat high-tech looking john. “I got myself an incinerating toilet. If you need to use it, let me know and I’ll explain how it works.” Well, nature never called during my visit to the boathouse, but I am still curious about how exactly an incinerating toilet operates. Are there any eco-advantages of one compared to, let’s say, a composting toilet?

A: Personally, I’ve “experienced” an incinerating toilet on only one occasion and, well, it was rather intimidating. Several years, ago I was visiting a friend at her parents’ home and they too had recently just completed construction on a tricked-out, très romantique boathouse/bunkhouse that was built at a formidable distance from the main house … so formidable that when you really had to go, things got logistically complicated.

Let’s just say that on this specific occasion, it was late into the night and I had previously enjoyed a few adult cocktails — getting myself to the main house when my colon began to rumble wasn’t going to happen. And so I resorted, flashlight in hand, to the incinerating toilet, a gizmo that, like a kitchen appliance, you plug in and turn on with the push of a button. But the similarities to kitchen appliances end there, as I discovered that using one involves placing a paper cone within the bowl and then, after you’ve done your business, stepping on a foot pedal to release the waste (cone included) into a fiery cauldron (aka the incinerating chamber) below where the waste is reduced to a small pile of ash. Needless to say, you probably shouldn’t remain seated on the toilet itself while stepping on the foot pedal although many models of incinerating toilets boast a safety feature that automatically powers off the incinerator while the device’s lid is up. Thank goodness for that.

Despite my scary, intoxicated run-in with incinerating toilets, they’ve emerged as a popular and easy-to-maintain alternative to composting toilets when septic or traditional sewer systems aren’t an option. According to top manufacturer Incinolet, the perks of incinerating toilets are numerous: they’re sanitary, odor-free and, unlike composting toilets, don’t require additives or chemicals. Additionally, the sterile ash produced by the toilets (about a tablespoon of ash per single use according to the EPA) is completely bacteria-free, so there are no restrictions on its disposal. However, since any nutrients have burned away in the heating process, the ash isn’t worth adding to a garden as a soil amendment — it’s best just to add it to your normal household trash.

And, of course, the biggest eco-benefit of torching your number twos: Zero water is required. Even with some models of composting toilets, water use is required, but with incinerating toilets, not a single drop is needed. But along with water conservation comes the main eco-disadvantage of incinerating toilets: You’ll need juice, mainly in the form of electricity, to cook your pee and poo. Models that run off of propane, diesel and natural gas are also available from manufacturers like Ecojohn. Popular electric models are 120 volts and consume 1.5 kilowatt hours of electricity per cycle … nothing crazy but with regular use, you’ll probably see a bump in your utility bills. Ecojohn estimates that the company’s propane, natural gas and diesel-fueled SR series of toilets cost around 8 to 10 cents per flush.

So there you have it … incinerating toilets 101. While not completely pollution-free, burning your waste instead of flushing or composting it does have its environmental and financial advantages, especially compared to septic installation. Next time you’re visiting your brother-in-law’s fancypants boathouse, I recommend giving his a spin if nature indeed calls. Just don’t follow in my footsteps and attempt to do it in the dark after a round of strong cocktails.